The closures in current use include plastic and metal closures for closing glass jars including baby food, peanuts and all sorts of other foods and non-food products. Some closures are snapped on and off, other closures are twisted on and off and still other closures are snapped on, and twisted off. In almost all cases, these closures are totally removed from the container, to open the container for product removal, except for some tamper bands which have portions that are retained around the neck of the jar or bottle.
The current closure concepts require design and manufacturing sensitivity to removal torques and forces while avoiding contamination under the exterior flange of the closure cap. At the same time, leakage due to discontinuity in the closure or closure gasket and the glass of the container must be avoided. Also, tamper evidence is limited in many cases to a metal button which responds to the loss of vacuum when the closure is opened.